You probably want to have a space ( ) character, but also set the values on the first tab correctly-ish
{
"$baseURI": "https://yal.cc/r/20/pixelfont/",
"$version": "1.0",
"in-glyphs": [
" ",
"ABCDEFGH",
"IJKLMNOP",
"QRSTUVWX",
"YZ",
"abcdefgh",
"ijklmnop",
"qrstuvwx",
"yz123456",
"7890~!@#",
"$%^&*()_",
"+`-=[];'",
"\\,./{}:\"",
"|<>?"
],
"glyph-color": "auto",
"in-kerning": [
""
],
"glyph-width": 5,
"glyph-height": 6,
"glyph-ofs-x": 1,
"glyph-ofs-y": 1,
"glyph-sep-x": 1,
"glyph-sep-y": 1,
"glyph-base-x": 0,
"glyph-baseline": 5,
"glyph-spacing": 1,
"font-is-mono": false,
"font-em-square": 1024,
"font-line-gap": 512,
"font-ascend": 512,
"font-descend": 0,
"font-px-size": 128,
"font-name": "Mystery Font",
"font-author": "You, of course",
"font-copy": "(c)",
"font-version": "Version 1.0",
"font-desc": "Sweet fonts to leave your worries behind you",
"font-license": "You have the permission",
"font-license-url": "",
"font-sample-text": "Hello!",
"font-preview-text": [
"THE QUICK BROWN FOX JUMPS OVER A LAZY DOG.",
"the quick brown fox jumps over a lazy dog.",
"0123456789"
]
}
